First dairy prices shot up. Then meat and seafood followed suit. Now higher grain costs are causing the cost of bread to rise.

Steve Adams

First dairy prices shot up. Then meat and seafood followed suit. Now higher grain costs are causing the cost of bread to rise.

It all adds up to steeper prices on the menu, and small independent restaurants are feeling the pinch. They're weighing whether to eat the costs or try to pass them along to diners.

''It's been really challenging,'' said Mark Vierbickas, executive chef at the Siros restaurant in Quincy's Marina Bay. ''Every missed cut and little piece of waste just knocks up your costs.''

Food prices rose 4.2 percent during the 12 months that ended in July, according to the U.S. Commerce Department. Many categories rose by double digits, including eggs, chicken and milk.

The price hikes stem from a confluence of factors.

Increased demand for ethanol as a fuel source has contributed to a steep increase in the price of corn in the past year. That, in turn, has boosted farmers' costs to buy feed for livestock. Fresh chicken prices have risen 10 percent in the past year, according to the Commerce Department.

Rising demand for food supplies in China and India has pushed global prices higher. And the lingering high cost of fuel has prompted many food suppliers to tack surcharges on deliveries to restaurants.

Even national chains such as West Roxbury-based Uno Restaurant Holdings Corp. are feeling the effects.

Larger operators have the ability to negotiate annual contracts with suppliers and lock in fixed prices on commodities such as beef and chicken, so they can temporarily avoid increased costs.

But Uno, which operates more than 200 Uno Chicago Grill restaurants in 29 states, has been affected by last month's increase in the federal minimum wage from $5.15 to $5.85 an hour. The company raised beverage prices this summer to offset the cost, CEO Frank Guidara said.

''In today's cost climate, if you're not up 3 to 4 percent in sales, you're having a difficult time paying the increasing cost of commodities and everything else,'' Guidara said.

Using drink prices to offset rising costs isn't possible for high-end restaurants such as Siros, which derives about 70 percent of its sales from food. Vierbickas estimated Siros' food costs have risen 5 percent in the past year. He's thinking about adding more vegetarian entrees to hold costs down.

Most suppliers now impose up to a $3 fuel charge per delivery, Vierbickas said. Swordfish and halibut, which had cost as little as $7 a pound last year, now cost up to $11 a pound, and lobster has increased from $5.75 to $10 a pound. Most recently, the price of baby spinach and mixed greens shot up because of dry weather in California's ''Salad Bowl'' produce region.

Elio Ricci, owner of the Raffael's restaurants in Hull and Walpole, said he's been trying to limit menu price increases to avoid driving away customers. Ricci's restaurants have been paying higher food costs and fuel surcharges to vendors.

''It just comes off the bottom line,'' Ricci said. ''We're making less of a profit than we were in past years.''

Rising wheat prices are translating into bigger bread bills for many eateries.

Wheat futures are trading at a 10-year high on the Chicago Board of Trade, driven by poor growing conditions that have depressed harvests in the U.S. and abroad. Local bakeries recently notified the Tavern at Quarry Hills in Quincy of a 40 percent increase in bread prices, food and beverage director Brian Leonard said.

''You can't really pass along all the increases to the customer,'' Leonard said. ''If something goes up 40 percent, you can't raise the price 40 percent. It's a juggling act.''

Fireking Baking Co. of Weymouth has been hit with more than a half-million-dollar increase in flour costs in the past year as the price of flour has risen from 11 cents a pound to 22 cents a pound, owner Greg Acerra said. The company sells its products at restaurants and manufactures private-label breads for grocery and discount club chains.

''I can't raise my price every week, but the price is going up so fast you can't control it,'' Acerra said.

If all of the costs remain at current levels, restaurants will have no choice but to pass the costs on to customers, said Darren Tristano, executive vice president at Chicago-based restaurant consultants Technomic.

''It's getting to a point where operators have to raise prices,'' he said.

Restaurants are looking for savings in other areas, such as cutting utility costs, and trying to maximize their food investment by reusing leftovers in soups or other items, Tristano said.

High-end chains will suffer from the trend the most, Tristano said, as consumers seek out mainstream casual chains with average checks of $30 to $35.